Evidence, broadly construed, is anything presented in support of an assertion. This support may be strong or weak. The strongest type of evidence is that which provides direct proof of the truth of an assertion. At the other extreme is evidence that is merely consistent with an assertion but does not rule out other, contradictory assertions, as in circumstantial evidence.
In law, rules of evidence govern the types of evidence that are admissible in a legal proceeding. Types of legal evidence include testimony, documentary evidence, and physical evidence. The parts of a legal case which are not in controversy are known, in general, as the "facts of the case." Beyond any facts that are undisputed, a judge or jury is usually tasked with being a trier of fact for the other issues of a case. Evidence and rules are used to decide questions of fact that are disputed, some of which may be determined by the legal burden of proof relevant to the case. Evidence in certain cases (e.g. capital crimes) must be more compelling than in other situations (e.g. minor civil disputes), which drastically affects the quality and quantity of evidence necessary to decide a case.
In a criminal trial in the United States, for example, the prosecution carries the burden of proof since the defendant is presumed innocent until proven guilty beyond a reasonable doubt. Similarly, in most civil procedures, the plaintiff carries the burden of proof and must convince a judge or jury that the preponderance of the evidence is on their side. Other legal standards of proof include "reasonable suspicion", "probable cause" (as for arrest), "prima facie evidence", "credible evidence", "substantial evidence", and "clear and convincing evidence".
In a philosophical debate, there is an implicit burden of proof on the party asserting a claim, since the default position is generally one of neutrality or unbelief. Each party in a debate will therefore carry the burden of proof for any assertion they make in the argument, although some assertions may be granted by the other party without further evidence. If the debate is set up as a resolution to be supported by one side and refuted by another, the overall burden of proof is on the side supporting the resolution.